Add (untested) HTTP write API

api.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bufio"
 	"context"
 	"crypto/ed25519"
 	"encoding/base64"
@@ -15,6 +16,7 @@ import (
 
 	"github.com/golang-jwt/jwt/v4"
 	"github.com/gorilla/mux"
+	"github.com/influxdata/line-protocol/v2/lineprotocol"
 )
 
 // Example:
@@ -208,6 +210,22 @@ func handlePeek(rw http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func handleWrite(rw http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(rw, "Method Not Allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	reader := bufio.NewReader(r.Body)
+	dec := lineprotocol.NewDecoder(reader)
+	// Unlike the name suggests, handleLine can handle multiple lines
+	if err := handleLine(dec); err != nil {
+		http.Error(rw, err.Error(), http.StatusBadRequest)
+		return
+	}
+	rw.WriteHeader(http.StatusOK)
+}
+
 func authentication(next http.Handler, publicKey ed25519.PublicKey) http.Handler {
 	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
 		authheader := r.Header.Get("Authorization")
@@ -244,6 +262,7 @@ func StartApiServer(address string, ctx context.Context) error {
 	r.HandleFunc("/api/{from:[0-9]+}/{to:[0-9]+}/stats", handleStats)
 	r.HandleFunc("/api/{to:[0-9]+}/free", handleFree)
 	r.HandleFunc("/api/{cluster}/peek", handlePeek)
+	r.HandleFunc("/api/write", handleWrite)
 
 	server := &http.Server{
 		Handler:      r,

lineprotocol.go

@@ -1,11 +1,9 @@
 package main
 
 import (
-	"bufio"
 	"context"
 	"log"
 	"math"
-	"net"
 	"strconv"
 	"sync"
 
@@ -53,48 +51,10 @@ type Metric struct {
 	Value Float
 }
 
-// Listen for connections sending metric data in the line protocol format.
-//
-// This is a blocking function, send `true` through the channel argument to shut down the server.
-// `handleLine` will be called from different go routines for different connections.
-//
-func ReceiveTCP(address string, handleLine func(dec *lineprotocol.Decoder), done chan bool) error {
-	ln, err := net.Listen("tcp", address)
-	if err != nil {
-		return err
-	}
-
-	go func() {
-		for {
-			stop := <-done
-			if stop {
-				err := ln.Close()
-				if err != nil {
-					log.Printf("closing listener failed: %s\n", err.Error())
-				}
-				return
-			}
-		}
-	}()
-
-	for {
-		conn, err := ln.Accept()
-		if err != nil {
-			return err
-		}
-
-		go func() {
-			reader := bufio.NewReader(conn)
-			dec := lineprotocol.NewDecoder(reader)
-			handleLine(dec)
-		}()
-	}
-}
-
 // Connect to a nats server and subscribe to "updates". This is a blocking
 // function. handleLine will be called for each line recieved via nats.
 // Send `true` through the done channel for gracefull termination.
-func ReceiveNats(address string, handleLine func(dec *lineprotocol.Decoder), workers int, ctx context.Context) error {
+func ReceiveNats(address string, handleLine func(dec *lineprotocol.Decoder) error, workers int, ctx context.Context) error {
 	nc, err := nats.Connect(nats.DefaultURL)
 	if err != nil {
 		return err
@@ -113,7 +73,9 @@ func ReceiveNats(address string, handleLine func(dec *lineprotocol.Decoder), wor
 			go func() {
 				for m := range msgs {
 					dec := lineprotocol.NewDecoderWithBytes(m.Data)
-					handleLine(dec)
+					if err := handleLine(dec); err != nil {
+						log.Printf("error: %s\n", err.Error())
+					}
 				}
 
 				wg.Done()
@@ -126,7 +88,9 @@ func ReceiveNats(address string, handleLine func(dec *lineprotocol.Decoder), wor
 	} else {
 		sub, err = nc.Subscribe("updates", func(m *nats.Msg) {
 			dec := lineprotocol.NewDecoderWithBytes(m.Data)
-			handleLine(dec)
+			if err := handleLine(dec); err != nil {
+				log.Printf("error: %s\n", err.Error())
+			}
 		})
 	}
 

metric-store.go

@@ -52,18 +52,18 @@ func loadConfiguration(file string) Config {
 	return config
 }
 
-func handleLine(dec *lineprotocol.Decoder) {
+func handleLine(dec *lineprotocol.Decoder) error {
 	for dec.Next() {
 		measurement, err := dec.Measurement()
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
 
 		var cluster, host, typeName, typeId string
 		for {
 			key, val, err := dec.NextTag()
 			if err != nil {
-				log.Fatal(err)
+				return err
 			}
 			if key == nil {
 				break
@@ -79,7 +79,7 @@ func handleLine(dec *lineprotocol.Decoder) {
 			case "type-id":
 				typeId = string(val)
 			default:
-				log.Fatalf("Unkown tag: '%s' (value: '%s')", string(key), string(val))
+				return fmt.Errorf("unkown tag: '%s' (value: '%s')", string(key), string(val))
 			}
 		}
 
@@ -94,7 +94,7 @@ func handleLine(dec *lineprotocol.Decoder) {
 		for {
 			key, val, err := dec.NextField()
 			if err != nil {
-				log.Fatal(err)
+				return err
 			}
 
 			if key == nil {
@@ -102,7 +102,7 @@ func handleLine(dec *lineprotocol.Decoder) {
 			}
 
 			if string(key) != "value" {
-				log.Fatalf("Unkown field: '%s' (value: %#v)", string(key), val)
+				return fmt.Errorf("unkown field: '%s' (value: %#v)", string(key), val)
 			}
 
 			if val.Kind() == lineprotocol.Float {
@@ -110,21 +110,22 @@ func handleLine(dec *lineprotocol.Decoder) {
 			} else if val.Kind() == lineprotocol.Int {
 				value = Float(val.IntV())
 			} else {
-				log.Fatalf("Unsupported value type in message: %s", val.Kind().String())
+				return fmt.Errorf("unsupported value type in message: %s", val.Kind().String())
 			}
 		}
 
 		t, err := dec.Time(lineprotocol.Second, time.Now())
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
 
 		if err := memoryStore.Write(selector, t.Unix(), []Metric{
 			{Name: string(measurement), Value: value},
 		}); err != nil {
-			log.Fatal(err)
+			return err
 		}
 	}
+	return nil
 }
 
 func intervals(wg *sync.WaitGroup, ctx context.Context) {